Everett smelter residential cleanup and sampling

The basic approach for cleaning up contaminated soil in the upland area is to remove soil that is most accessible to people, especially children.

The program is free to all properties in the Everett smelter cleanup area and completely voluntary. We work first in areas where contamination is highest. These areas are generally closest to the former smelter site.


Picture of a person sampling soil with a hand auger.

First, properties are sampled to determine if the soil contains arsenic above state cleanup levels. If contamination is found above these levels, cleanup is recommended.

If your property still needs sampling, please contact us. Click the links above to find out if your property is within the boundary, and if it has already been sampled or cleaned up.

What does soil testing look like?

We will contact you for permission to enter your yard. We will collect multiple soil samples using a tool called an auger (see photo). The auger takes a sample that is two inches in diameter and two feet deep. The samples are tested on-site to find out if arsenic is present above state cleanup levels, and a portion of those samples are also sent to a lab for confirmation.

My yard is inside the cleanup site boundary and I want my soil tested. What should I do?

We are sampling properties and cleaning up the site as funding is available. Our approach has been to work on properties closest to the former smelter first since they generally have higher levels of contamination. Our sampling and cleanup work continues to move further out from the former smelter site.

If you would like to have your soil tested before we are able to, you can choose to sample your property yourself. We recommend that you follow the Soil Sampling Guidance developed for the Tacoma smelter plume.

My yard is outside the cleanup site boundary and I want my soil tested. What should I do?

We are not currently sampling properties outside the cleanup site boundary. If you would like to have your soil tested, you can choose to sample your property yourself. We recommend that you follow the Soil Sampling Guidance developed for the Tacoma smelter plume site.


Pictures of a home before, during, and after cleanup. The before picture shows patchy grass. The during cleanup picture shows dirt and earthmoving equipment. The after pictures shows a landscaped yard

Residential cleanup involves removal of contaminated soil, replacement with clean soil, and landscape restoration. We will not sample or clean up any property without permission from the property owner.

Read more about the process

Watch a video of the cleanup.

My property was sampled and Ecology recommended cleanup, but I haven't been contacted by anyone yet. What's the next step?

If your property has been sampled, we have you on our list of properties that need cleanup. We are currently creating cleanup groups for the coming years. 

We will keep you informed about project status through our website and mailings. Please call our project hotline at 425-446-1024 if you have any questions.

What is the cleanup level for arsenic in the Everett smelter plume site?

The cleanup level for arsenic on the Everett smelter site is 20 ppm (parts per million) in the top 12 inches of soil. This is considered the “urban background” level for Washington soils.

We calculate and set cleanup levels based on risk of impacts and exposure, according to state law (Chapter 173-340 WAC Model Toxics Control Act).

How much soil will you remove from my property?

We use your soil sampling results as a guide to determine how much soil will be removed from your property. In 1999, we developed a framework for soil removal decisions as part of the cleanup action plan. Extensive public input was used to develop this framework.

We use the guidelines in the table below to determine whether soil needs to be removed. A higher contamination threshold is used at greater depths, because it is less likely that people will come in contact with soil at deeper levels.

Depth of Soil

Average Arsenic Level

Maximum Arsenic Level
(at one sample point)

0-12 inches

20 ppm

40 ppm

12-24 inches

60 ppm

150 ppm

24-36 inches*

150 ppm

500 ppm

*Currently we do not sample soil below 24 inches.

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